1. Field of the Invention
The present invention relates to head worn audio headsets. More particularly, the present invention relates to radio wireless headsets that employ an air tube acoustically coupled earpiece.
2. Description of the Related Art
Wireless earphones and headset are known. These include monaural and stereo listen-only headsets and headsets used in telephony and radiotelephony that include a microphone for enabling duplex communications. A common application for wireless headsets is use in conjunction with a cellular telephone. A cellular telephone is carried by a user, and is used for interconnection with a cellular telephone network. The cellular telephone additionally includes a separate wireless transceiver, commonly a Bluetooth compliant transceiver. The Bluetooth transceiver in the cellular telephone wirelessly communicates with a compact, head worn wireless headset. These are commonly referred to as Bluetooth headsets. The Bluetooth headset itself comprises a compact Bluetooth transceiver, a battery, an earphone, and limited user interface components. In operation, the cellular telephone functions to engage in telephone calls through the cellular network, and the Bluetooth headset enables the user to listen and speak in a hands free mode of operation without the need for a wire or cable between the cellular telephone and the headset. The Bluetooth transceivers in the cellular telephone and in the wireless headset provide the needed communications link therebetween.
Many users of wireless device and certain medical professionals have indicated a concern in regards to the extended use of wireless devices in the vicinity of the human brain. The concern relates to the possibility of radiational damage cause by the absorption of radio energy in the brain tissues. In fact, a reason that cellular telephone users employ headsets is the understanding that the cellular radio, being positioned a distance away from the user's brain, will result in lower radiated power levels, and thus lower radiation risk. However, in the case of a wired headset, the radio energy originating in the radio transceiver excites the audio conductors coupled to the headset, and results in radio energy being present in the acoustic driver, or speaker, as well as the microphone in the headset. Thus, the user is effectively coupling the radio energy to a position directly adjacent to their ear and brain. Other users employ the aforementioned Bluetooth wireless headsets, understanding that the wireless headset breaks the conductive link for radio energy from the cellular telephone, thereby preventing the cellular transceiver's energy from significantly coupling into the brain tissue.
Bluetooth transceivers operating in the 2.4 GHz ISM band, which is a frequency band known to be absorbed into brain tissue. Even though the transmitter power levels of Bluetooth transceivers are relatively low as compared to cellular transceiver power levels, the fact that the Bluetooth headset transceivers are worn directly adjacent to the user's ear and brain, creates the worst case scenario for radiational damage exposure, particularly given the absorptive nature of the 2.4 GHz operating band in brain tissue. Thus, users who chose to use a Bluetooth headset to avoid cellular radiation exposure risk, are actually substituting that exposure risk for another risk. Thus, it can be appreciated that there is a need in the art to reduce the risk of radiation exposure to users of wireless headset devices.